1. Field of the Invention
This invention pertains generally to television and other video displays and, more particularly, to a system and method for viewing video images in three dimensions.
2. Description of The Related Art
Three dimensional realism or depth perception can be added to motion picture and television presentations by providing separate left and right images of an object or scene from slightly displaced points of view and presenting these images to the respective eyes of the viewers. To be effective, it is important that left eyes receive only the left images and the right eyes receive only the right images.
In the past, one method of separating the two images involved the use of color filters in preparing the images and in viewing them. This method was used both for printed media and for film media such as the motion picture industry. The quality of images produced by this technique was limited by the quality of the filters, and only moderate image separation was possible. Another problem with this technique was that the filters attenuated all of the light passing through them to some extent, with the result that the viewed images did not have very high contrast and were not as bright as they should have been. Also, it was not possible to broadcast television images in black and white using the color filtering technique, thus limiting the technique to color transmissions only.
For motion pictures, polarizing filters have been employed to separate the images for the respective eyes. The two images are projected onto the screen simultaneously, and the viewers are provided with eyeglasses having polarized lenses which are intended to pass the left and right images to the respective eyes. This technique provides less attenuation and distortion than the color filter technique, and it has met with moderate success. It is still used occasionally.
U.S. Pat. No. 4,461,541 describes a technique in which polarizing lenses or filters are employed to provide stereoscopic images of pictures displayed on a television monitor.
U.S. Pat. No. 3,621,127 describes a three dimensional system in which the two spatially displaced images are projected onto a screen sequentially, rather than simultaneously, and viewers are provided with spectacles having mechanical shutters for alternately exposing the left and right eyes to the images. In this system, there is a problem in providing synchronization between the image source and the spectacles to insure that the proper images are presented to the respective eyes.
It is in general an object of the invention to provide a new and improved stereoscopic video system and method.
Another object of the invention is to provide a system and method of the above character which overcome the limitations and disadvantages of stereoscopic systems heretofore provided.
Another object of the invention is to provide a system and method of the above character in which presentation of the images to the proper eyes is accurately synchronized.
Another object of the invention is to provide a system and method of the above character in which brightness or intensity of the images is limited to eliminate flicker in the stereoscopic image.